/*
 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.eclipse.imagen.media.opimage;

import java.awt.Rectangle;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.IndexColorModel;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import java.util.Map;
import org.eclipse.imagen.BorderExtender;
import org.eclipse.imagen.ImageLayout;
import org.eclipse.imagen.Interpolation;
import org.eclipse.imagen.RasterAccessor;
import org.eclipse.imagen.RasterFormatTag;
import org.eclipse.imagen.ScaleOpImage;
import org.eclipse.imagen.media.util.Rational;
// import org.eclipse.imagen.media.test.OpImageTester;

/** An OpImage subclass that performs nearest-neighbor scaling. */
final class ScaleNearestOpImage extends ScaleOpImage {

    long invScaleXInt, invScaleXFrac;
    long invScaleYInt, invScaleYFrac;

    /**
     * Constructs a ScaleNearestOpImage from a RenderedImage source,
     *
     * @param source a RenderedImage.
     * @param layout an ImageLayout optionally containing the tile grid layout, SampleModel, and ColorModel, or null.
     * @param xScale scale factor along x axis.
     * @param yScale scale factor along y axis.
     * @param xTrans translation factor along x axis.
     * @param yTrans translation factor along y axis.
     * @param interp an Interpolation object to use for resampling.
     */
    public ScaleNearestOpImage(
            RenderedImage source,
            BorderExtender extender,
            Map config,
            ImageLayout layout,
            float xScale,
            float yScale,
            float xTrans,
            float yTrans,
            Interpolation interp) {
        super(source, layout, config, true, extender, interp, xScale, yScale, xTrans, yTrans);

        // If the source has an IndexColorModel, override the default setting
        // in OpImage. The dest shall have exactly the same SampleModel and
        // ColorModel as the source.
        // Note, in this case, the source should have an integral data type.
        ColorModel srcColorModel = source.getColorModel();
        if (srcColorModel instanceof IndexColorModel) {
            sampleModel = source.getSampleModel().createCompatibleSampleModel(tileWidth, tileHeight);
            colorModel = srcColorModel;
        }

        if (invScaleXRational.num > invScaleXRational.denom) {
            invScaleXInt = invScaleXRational.num / invScaleXRational.denom;
            invScaleXFrac = invScaleXRational.num % invScaleXRational.denom;
        } else {
            invScaleXInt = 0;
            invScaleXFrac = invScaleXRational.num;
        }

        if (invScaleYRational.num > invScaleYRational.denom) {
            invScaleYInt = invScaleYRational.num / invScaleYRational.denom;
            invScaleYFrac = invScaleYRational.num % invScaleYRational.denom;
        } else {
            invScaleYInt = 0;
            invScaleYFrac = invScaleYRational.num;
        }
    }

    /**
     * Performs a scale operation on a specified rectangle. The sources are cobbled.
     *
     * @param sources an array of source Rasters, guaranteed to provide all necessary source data for computing the
     *     output.
     * @param dest a WritableRaster containing the area to be computed.
     * @param destRect the rectangle within dest to be processed.
     */
    protected void computeRect(Raster[] sources, WritableRaster dest, Rectangle destRect) {
        // Retrieve format tags.
        RasterFormatTag[] formatTags = getFormatTags();

        Raster source = sources[0];

        // Get the source rectangle
        Rectangle srcRect = source.getBounds();

        int srcRectX = srcRect.x;
        int srcRectY = srcRect.y;

        RasterAccessor srcAccessor =
                new RasterAccessor(source, srcRect, formatTags[0], getSource(0).getColorModel());

        RasterAccessor dstAccessor = new RasterAccessor(dest, destRect, formatTags[1], getColorModel());

        int srcScanlineStride = srcAccessor.getScanlineStride();
        int srcPixelStride = srcAccessor.getPixelStride();

        // Destination rectangle dimensions.
        int dx = destRect.x;
        int dy = destRect.y;
        int dwidth = destRect.width;
        int dheight = destRect.height;

        // Precalculate the x positions and store them in an array.
        int[] xvalues = new int[dwidth];

        long sxNum = dx, sxDenom = 1;

        // Subtract the X translation factor sx -= transX
        sxNum = sxNum * transXRationalDenom - transXRationalNum * sxDenom;
        sxDenom *= transXRationalDenom;

        // Add 0.5
        sxNum = 2 * sxNum + sxDenom;
        sxDenom *= 2;

        // Multply by invScaleX
        sxNum *= invScaleXRationalNum;
        sxDenom *= invScaleXRationalDenom;

        // Separate the x source coordinate into integer and fractional part
        // int part is floor(sx), frac part is sx - floor(sx)
        int srcXInt = Rational.floor(sxNum, sxDenom);
        long srcXFrac = sxNum % sxDenom;
        if (srcXInt < 0) {
            srcXFrac = sxDenom + srcXFrac;
        }

        // Normalize - Get a common denominator for the fracs of
        // src and invScaleX
        long commonXDenom = sxDenom * invScaleXRationalDenom;
        srcXFrac *= invScaleXRationalDenom;
        long newInvScaleXFrac = invScaleXFrac * sxDenom;

        for (int i = 0; i < dwidth; i++) {

            // Calculate the position
            xvalues[i] = (srcXInt - srcRectX) * srcPixelStride;

            // Move onto the next source pixel.

            // Add the integral part of invScaleX to the integral part
            // of srcX
            srcXInt += invScaleXInt;

            // Add the fractional part of invScaleX to the fractional part
            // of srcX
            srcXFrac += newInvScaleXFrac;

            // If the fractional part is now greater than equal to the
            // denominator, divide so as to reduce the numerator to be less
            // than the denominator and add the overflow to the integral part.
            if (srcXFrac >= commonXDenom) {
                srcXInt += 1;
                srcXFrac -= commonXDenom;
            }
        }

        // Precalculate the y positions and store them in an array.
        int[] yvalues = new int[dheight];

        long syNum = dy, syDenom = 1;

        // Subtract the X translation factor sy -= transY
        syNum = syNum * transYRationalDenom - transYRationalNum * syDenom;
        syDenom *= transYRationalDenom;

        // Add 0.5
        syNum = 2 * syNum + syDenom;
        syDenom *= 2;

        // Multply by invScaleX
        syNum *= invScaleYRationalNum;
        syDenom *= invScaleYRationalDenom;

        // Separate the x source coordinate into integer and fractional part
        int srcYInt = Rational.floor(syNum, syDenom);
        long srcYFrac = syNum % syDenom;
        if (srcYInt < 0) {
            srcYFrac = syDenom + srcYFrac;
        }

        // Normalize - Get a common denominator for the fracs of
        // src and invScaleY
        long commonYDenom = syDenom * invScaleYRationalDenom;
        srcYFrac *= invScaleYRationalDenom;
        long newInvScaleYFrac = invScaleYFrac * syDenom;

        for (int i = 0; i < dheight; i++) {

            // Calculate the position
            yvalues[i] = (srcYInt - srcRectY) * srcScanlineStride;

            // Move onto the next source pixel.

            // Add the integral part of invScaleY to the integral part
            // of srcY
            srcYInt += invScaleYInt;

            // Add the fractional part of invScaleY to the fractional part
            // of srcY
            srcYFrac += newInvScaleYFrac;

            // If the fractional part is now greater than equal to the
            // denominator, divide so as to reduce the numerator to be less
            // than the denominator and add the overflow to the integral part.
            if (srcYFrac >= commonYDenom) {
                srcYInt += 1;
                srcYFrac -= commonYDenom;
            }
        }

        switch (dstAccessor.getDataType()) {
            case DataBuffer.TYPE_BYTE:
                byteLoop(srcAccessor, destRect, dstAccessor, xvalues, yvalues);
                break;

            case DataBuffer.TYPE_SHORT:
            case DataBuffer.TYPE_USHORT:
                shortLoop(srcAccessor, destRect, dstAccessor, xvalues, yvalues);
                break;

            case DataBuffer.TYPE_INT:
                intLoop(srcAccessor, destRect, dstAccessor, xvalues, yvalues);
                break;

            case DataBuffer.TYPE_FLOAT:
                floatLoop(srcAccessor, destRect, dstAccessor, xvalues, yvalues);
                break;

            case DataBuffer.TYPE_DOUBLE:
                doubleLoop(srcAccessor, destRect, dstAccessor, xvalues, yvalues);
                break;

            default:
                throw new RuntimeException(JaiI18N.getString("OrderedDitherOpImage0"));
        }

        // If the RasterAccessor object set up a temporary buffer for the
        // op to write to, tell the RasterAccessor to write that data
        // to the raster no that we're done with it.
        if (dstAccessor.isDataCopy()) {
            dstAccessor.clampDataArrays();
            dstAccessor.copyDataToRaster();
        }
    }

    private void byteLoop(RasterAccessor src, Rectangle dstRect, RasterAccessor dst, int xvalues[], int yvalues[]) {

        int dwidth = dstRect.width;
        int dheight = dstRect.height;

        // Get destination related variables.
        byte dstDataArrays[][] = dst.getByteDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();
        int dnumBands = dst.getNumBands();

        // Get source related variables.
        int bandOffsets[] = src.getBandOffsets();
        byte srcDataArrays[][] = src.getByteDataArrays();

        int dstPixelOffset;
        int dstOffset = 0;
        int posy, posx, pos;

        int dstScanlineOffset;
        // For each band
        for (int k = 0; k < dnumBands; k++) {
            byte dstData[] = dstDataArrays[k];
            byte srcData[] = srcDataArrays[k];
            int bandOffset = bandOffsets[k];
            dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                dstPixelOffset = dstScanlineOffset;
                posy = yvalues[j] + bandOffset;
                for (int i = 0; i < dwidth; i++) {
                    posx = xvalues[i];
                    pos = posx + posy;
                    dstData[dstPixelOffset] = srcData[pos];
                    dstPixelOffset += dstPixelStride;
                }
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    private void shortLoop(RasterAccessor src, Rectangle dstRect, RasterAccessor dst, int xvalues[], int yvalues[]) {

        int dwidth = dstRect.width;
        int dheight = dstRect.height;

        // Get destination related variables.
        short dstDataArrays[][] = dst.getShortDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();
        int dnumBands = dst.getNumBands();

        // Get source related variables.
        int bandOffsets[] = src.getBandOffsets();
        short srcDataArrays[][] = src.getShortDataArrays();

        int dstPixelOffset;
        int dstOffset = 0;
        int posy, posx, pos;

        int dstScanlineOffset;
        // For each band
        for (int k = 0; k < dnumBands; k++) {
            short dstData[] = dstDataArrays[k];
            short srcData[] = srcDataArrays[k];
            int bandOffset = bandOffsets[k];
            dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                dstPixelOffset = dstScanlineOffset;
                posy = yvalues[j] + bandOffset;
                for (int i = 0; i < dwidth; i++) {
                    posx = xvalues[i];
                    pos = posx + posy;
                    dstData[dstPixelOffset] = srcData[pos];
                    dstPixelOffset += dstPixelStride;
                }
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    // identical to byteLoops, except datatypes have changed.  clumsy,
    // but there's no other way in Java
    private void intLoop(RasterAccessor src, Rectangle dstRect, RasterAccessor dst, int xvalues[], int yvalues[]) {

        int dwidth = dstRect.width;
        int dheight = dstRect.height;

        int dnumBands = dst.getNumBands();
        int dstDataArrays[][] = dst.getIntDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        int bandOffsets[] = src.getBandOffsets();
        int srcDataArrays[][] = src.getIntDataArrays();

        int dstPixelOffset;
        int dstOffset = 0;
        int posy, posx, pos;

        int dstScanlineOffset;
        // For each band
        for (int k = 0; k < dnumBands; k++) {
            int dstData[] = dstDataArrays[k];
            int srcData[] = srcDataArrays[k];
            int bandOffset = bandOffsets[k];
            dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                dstPixelOffset = dstScanlineOffset;
                posy = yvalues[j] + bandOffset;
                for (int i = 0; i < dwidth; i++) {
                    posx = xvalues[i];
                    pos = posx + posy;
                    dstData[dstPixelOffset] = srcData[pos];
                    dstPixelOffset += dstPixelStride;
                }
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    // identical to byteLoop, except datatypes have changed.  clumsy,
    // but there's no other way in Java
    private void floatLoop(RasterAccessor src, Rectangle dstRect, RasterAccessor dst, int xvalues[], int yvalues[]) {

        int dwidth = dstRect.width;
        int dheight = dstRect.height;

        int dnumBands = dst.getNumBands();
        float dstDataArrays[][] = dst.getFloatDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        float srcDataArrays[][] = src.getFloatDataArrays();
        int bandOffsets[] = src.getBandOffsets();

        int dstPixelOffset;
        int dstOffset = 0;
        int posy, posx, pos;

        int dstScanlineOffset;
        // For each band
        for (int k = 0; k < dnumBands; k++) {
            float dstData[] = dstDataArrays[k];
            float srcData[] = srcDataArrays[k];
            int bandOffset = bandOffsets[k];
            dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                dstPixelOffset = dstScanlineOffset;
                posy = yvalues[j] + bandOffset;
                for (int i = 0; i < dwidth; i++) {
                    posx = xvalues[i];
                    pos = posx + posy;
                    dstData[dstPixelOffset] = srcData[pos];
                    dstPixelOffset += dstPixelStride;
                }
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    // identical to byteLoop, except datatypes have changed.  clumsy,
    // but there's no other way in Java
    private void doubleLoop(RasterAccessor src, Rectangle dstRect, RasterAccessor dst, int xvalues[], int yvalues[]) {

        int dwidth = dstRect.width;
        int dheight = dstRect.height;

        int dnumBands = dst.getNumBands();
        double dstDataArrays[][] = dst.getDoubleDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        int bandOffsets[] = src.getBandOffsets();
        double srcDataArrays[][] = src.getDoubleDataArrays();

        int dstPixelOffset;
        int dstOffset = 0;
        int posy, posx, pos;

        int dstScanlineOffset;
        // For each band
        for (int k = 0; k < dnumBands; k++) {
            double dstData[] = dstDataArrays[k];
            double srcData[] = srcDataArrays[k];
            int bandOffset = bandOffsets[k];
            dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                dstPixelOffset = dstScanlineOffset;
                posy = yvalues[j] + bandOffset;
                for (int i = 0; i < dwidth; i++) {
                    posx = xvalues[i];
                    pos = posx + posy;
                    dstData[dstPixelOffset] = srcData[pos];
                    dstPixelOffset += dstPixelStride;
                }
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    //     public static OpImage createTestImage(OpImageTester oit) {
    // 	Interpolation interp =
    //             Interpolation.getInstance(Interpolation.INTERP_NEAREST);
    //         return new ScaleNearestOpImage(oit.getSource(), null,
    // 				       new ImageLayout(oit.getSource()),
    // 				       2.5F, 2.5F, 0.0F, 0.0F,
    //                                        interp);
    //     }

    //     public static void main(String args[]) {

    //         String classname = "org.eclipse.imagen.media.opimage.ScaleNearestOpImage";
    // 	OpImageTester.performDiagnostics(classname, args);
    // 	System.exit(1);

    // 	System.out.println("ScaleOpImage Test");
    //         ImageLayout layout;
    //         OpImage src, dst;
    //         Rectangle rect = new Rectangle(0, 0, 5, 5);

    // 	InterpolationNearest interp = new InterpolationNearest();

    //         System.out.println("1. PixelInterleaved short 3-band");
    //         layout = OpImageTester.createImageLayout(
    //             0, 0, 200, 200, 0, 0, 64, 64, DataBuffer.TYPE_SHORT, 3, false);
    //         src = OpImageTester.createRandomOpImage(layout);
    //         dst = new ScaleNearestOpImage(src, null, null,
    //                                       2.0F, 2.0F, 0.0F, 0.0F, interp);
    //         OpImageTester.testOpImage(dst, rect);
    //         OpImageTester.timeOpImage(dst, 10);

    //         System.out.println("2. PixelInterleaved ushort 3-band");
    //         layout = OpImageTester.createImageLayout(
    //             0, 0, 512, 512, 0, 0, 200, 200, DataBuffer.TYPE_USHORT, 3, false);
    //         src = OpImageTester.createRandomOpImage(layout);
    //         dst = new ScaleNearestOpImage(src, null, null,
    //                                       4.0F, 2.0F, 0.0F, 0.0F, interp);
    //         OpImageTester.testOpImage(dst, rect);
    //         OpImageTester.timeOpImage(dst, 10);
    //     }
}
